1. Field of the Invention
The present invention relates to a cleaning/drying apparatus and, more particularly, to wafer guides for holding semiconductor substrates.
2. Description of Related Art
A wet process, such as a wet cleaning process or a wet etching process, is frequently used in fabricating semiconductor devices. Semiconductor substrates, e.g., semiconductor wafers, are dipped into a chemical solution to perform the wet process. A portion of the chemical solution may remain on the semiconductor wafers even after finishing the wet process. The remaining chemical solution is removed by a rinse process. The rinse process is typically performed using de-ionized (DI) water. The DI water on the wafers is removed by a drying process.
A wafer guide holds the wafers during the wet processes, the rinse process, and the drying process. That is, the wafers are inserted into slots of the wafer guide. As a result, the wafers are in contact with the wafer guide. Accordingly, even though the drying process is performed, the DI water around contact points between the wafer guide and the wafers may not be removed. The DI water remaining on the wafers after the drying process generates surface defects called “water spots”. The water spots substantially reduce the yield of the semiconductor devices from the wafers. Therefore, there is a need to decrease the contact areas between the wafers and the wafer guide.
The slots of the wafer guide have widths greater than the thickness of the wafers. The width of the slots prevent scratches from being formed on the surfaces of the wafers when the wafers are loaded into the slots. Each of the wafers loaded in the slots randomly inclines to one side and therefore, spaces between the wafers are irregular. In particular, when the spaces between the front surfaces of the adjacent wafers are non-uniform, the drying efficiency of the drying process is substantially reduced.